Utilities and Hydro Excavation

Case Study

Utilities - A Hydro Excavation Case Study

Overview of The Customer

Based in San Francisco, California, this major utility is one of the largest combined natural gas and electric energy companies in the United States. This long-standing business has been operating for over a century and has over 23,000 employees providing natural gas and electric services to over 16 million people.

Pain Point

The company had directed that all wet spoils and fluids generated from underground operations and maintenance activities be brought back to their own sites. At these sites, subcontractors were used to manage the vacuum excavated material. The process involved collecting the vac material in large tanks, letting the solids settle out, removing the surface water, and finally adding a dry bulking agent to the residual slurry. These dry bulking agents were inefficient as they can add as much as 200% in waste volume and will release fluids in transportation. With an excessive amount of added material to meet solids criteria for disposal, the utility company was incurring significant costs related to transportation, disposal, and labor.

 

Decision Process

MetaFLO reached out to the company in 2014 as a prospect with high opportunity for process improvement benefits. The company was looking for a solution that would continue to mitigate the risks of liquid waste disposal while reducing cost and improving efficiency. MetaFLO was the optimal choice considering its fast, efficient, and cost effective process.

Implementation

The company had pre-existing infrastructure to receive hydro-excavated liquid waste at their facilities. The transition to utilizing MetaFLO technology was immediate and seamless. They simply mixed MetaFLO’s reagent into the vac material to get a dry, earthlike solid, ready for transportation and disposal. Taking only three months from initial product introduction through comprehensive pilot trials to full implementation, this was a solution for the company that was easy to carry out with existing infrastructure and resulted in much less waste and reduced total cost.

 

How it Works

After implementing MetaFLO’s solidification technology, the utility company’s contractor found a disposal application for the treated material that would reduce costs further. Landfills have a need for day-cover, a layer of compressed soil that prevents each day’s deposition of waste from spreading.The treated material was utilized as day-cover at 2 local landfill sites that would accept the treated waste, to address their daily needs at no cost.

 

 

Results

By implementing MetaFLO’s process, the utility company was able to achieve a multitude of positive results. With MetaFLO’s fast-acting reagent, they were able to,

  • Reduce the time required to meet solids criteria for disposal
  • Eliminate the dry, bulking agents required on-site
  • Realize a 0.5% wt/wt addition rate of MetaFLO’s reagent to meet solids criteria
  • Reduced the total volume of waste transported off site
  • Reduce the number of heavy trucks on the road
  • Utilize waste material for beneficial reuse
  • Lower GHG emissions.

Ultimately, the company significantly simplified their liquid waste disposal process and reduced total costs by almost 30%.

 

 

Cabonne Shire WWT Lagoons

Key Stakeholders:

Owner: Vale Canada Ltd.
Contractor: Tervita Corp.
Distributor: Di-Corp

vale-tervita-di-corp

Challenge

Vale owns and operates a mining site in Northern Ontario, Canada. Through their mining and refining activities they produce a sludge waste by-product. The clients were in need of an efficient excavation and transportation solution to get this sludge to their off-site landfill.

Date

End of September 2018  -  Mid October 2018

Solution

During the bidding process, MetaFLO was engaged to provide an optimal blend and dosage rate to achieve the solids criteria required for excavation and transportation of the sludge. Using analytical data, MetaFLO estimated a dosage rate of 1.1% by weight (based on a high moisture content). Large mixing bins were recommended for increased surface contact and efficiency during the bucket mixing process. No sample was available at this time.

Result

Tervita Corporation utilized MetaFLO reagent to solidify approximately 4,000 m3 of sludge. Two 35m3 bins were staged on site and were loaded with a composite of “heavier” and “lighter” sludges. The originally estimated dosage rate was accurate as actual treatment averaged approximately 30lbs of MetaFLO MF006 reagent per m3 of sludge. All material was safely shipped to Vale’s off-site landfill. The job was completed on time.